SSL_ERROR_NO_CYPHER_OVERLAP on multiple websites (Firefox)

Hello,

Since today I’m not able (I have seen on social media, that I’m not the only one with this issue) to access websites behind CloudFlare on Firefox (ESR 78.14.0) I get “SSL_ERROR_NO_CYPHER_OVERLAP” error.

This happens on multiple websites and no changes was made to my browser recently.

So the ask is if something has changed in CloudFlare configuration recently or is it some kind of issue on CF side?

Run your web site through SSL Server Test (Powered by Qualys SSL Labs) to see if there’s any clues.

Do you have on your local PC running Firefox, any security software or antivirus software like Bitdefender? They could be man in the middle inspecting HTTPS requests and thus communicate with Cloudflare edge servers using incompatible/overlapping SSL ciphers. You can check by looking at your site’s SSL certificate if it belongs to Cloudflare or some other company in your Firefox browser. If that is the case, try turning off HTTPS inspection in your local PC security/antivirus software.

Also try updating Firefox versions

1 Like

It was solved by itself, so it was an issue with ciphers on CloudFlare side, pitty no info about that on status page.

Run your web site through SSL Server Test (Powered by Qualys SSL Labs) to see if there’s any clues.

Again it wasn’t problem with my website but many websites ruining behind CloudFlare.

Do you have on your local PC running Firefox, any security software or antivirus software like Bitdefender?

No software touching HTTPS traffic.

Also try updating Firefox versions

It’s up to date (no newer version on ESR chanel). Also what could update do (add support for new ciphers? it also means someone had to disable current ones first)

This topic was automatically closed 15 days after the last reply. New replies are no longer allowed.